Are brown dwarfs, white dwarfs, and neutrons stars kept from collapsing by degeneracy pressure?
1 Answer
No, yes and yes.
Explanation:
Brown dwarfs are not really stars (Jupiter is almost a brown dwarf). They do not have the gravity necessary to cause hydrogen fusion. What fusion does occur, deuterium and lithium, does not use up all the "fuel" of the object. As such it generates heat for a while but then just cools. As a result it never goes nova. As a result of that it never collapses, so it does not require anything to keep it from collapsing further.
White dwarfs and neutron stars are the end products of stars and therefore they undergo a cataclysmic collapse. The end product have extremely high density. The only thing that keeps them from collapsing further (forming a black hole I suppose) is degeneracy pressure or basically the pressure cause by two objects (in this case the objects would be subatomic particles) from occupying the same space.
